1. Field of the Invention
The present invention relates to an optical pickup and a method of manufacturing the same, and an optical information storage system including the optical pickup, and more particularly, to an ultra-small integrated optical pickup which can be mass produced in a simple process and a method of manufacturing the same, and an optical information storage system including the optical pickup.
2. Description of the Related Art
Optical information storage systems include optical pickup devices to record information on optical discs and/or reproduce the information from the optical discs. The optical information storage systems are different from other information storage systems in that they have the advantages of possibility of media distribution, portability, high capacity, prevention of information leakage, and so on.
Optical discs have been developed from compact discs (CDs) having a diameter of 12 cm and a substrate thickness of 1.2 mm to digital versatile discs (DVDs) having a diameter of 12 cm and a substrate thickness of 0.6 mm. Blu-ray discs are even thinner than DVDs. Optical information storage systems for recording information on the optical discs and reproducing the information from the optical discs are being developed to focus high optical energy on a small spot and achieve a high recording density keeping pace with the development of the optical information media. For example, optical information storage systems for CDs employ a light source having a wavelength of 780 nm and an objective lens having a numerical aperture (NA) of 0.45, and optical information storage systems for DVDs employ a light source having a wavelength of 650 nm and an objective lens having an NA of 0.6.
In recent years, as optical discs have been manufactured with higher density and higher capacity, numerous studies have been made to increase an NA of an objective lens to reduce the size of a light spot and manufacture thin-type optical parts to create an ultra-small optical pickup. Typically, attempts have been made to reduce the size of optical parts to reduce the entire size of an optical information storage system. However, this approach has technical limitations.
In this respect, an attempt to manufacture an optical pickup using a MEMS process has been made to solve the above problem. The conventional optical pickup manufacturing method suffers from low reliability and low automation ratio in adhering and adjusting ultra-small parts of several hundreds of microns due to an assembling error of the parts. However, when the optical pickup is manufactured using a MEMS process, the optical pickup can be batch-processed, thereby offering a possibility that an ultra-small optical pickup can be realized by integrating general electronic parts, and a price of an optical information storage system comprising the optical pickup can be reduced as well. However, the ultra-small optical pickup made using the semiconductor process and the optical information storage system comprising the pickup have not been developed yet.